Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932771Ab1EYUvV (ORCPT ); Wed, 25 May 2011 16:51:21 -0400 Received: from smtp-out.google.com ([74.125.121.67]:14056 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755914Ab1EYUvU (ORCPT ); Wed, 25 May 2011 16:51:20 -0400 From: Mandeep Singh Baines To: linux-kernel@vger.kernel.org, jrbarnette@chromium.org Cc: Mandeep Singh Baines , Neil Brown , Mike Snitzer , Jens Axboe , "Martin K. Petersen" , Alasdair G Kergon , dm-devel@redhat.com Subject: [PATCH] dm: pass up rotational flag Date: Wed, 25 May 2011 13:50:48 -0700 Message-Id: <1306356648-30730-1-git-send-email-msb@chromium.org> X-Mailer: git-send-email 1.7.3.1 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2350 Lines: 72 Allow the NONROT flag to be passed through to linear mappings if all underlying device are non-rotational. Tools like ureadahead will schedule IOs differently based on the rotational flag. With this patch, I see boot time go from 7.75 s to 7.46 s on my device. Suggested-by: J. Richard Barnette Signed-off-by: Mandeep Singh Baines Cc: Neil Brown Cc: Mike Snitzer Cc: Jens Axboe Cc: Martin K. Petersen Cc: Alasdair G Kergon Cc: dm-devel@redhat.com --- drivers/md/dm-table.c | 28 ++++++++++++++++++++++++++++ 1 files changed, 28 insertions(+), 0 deletions(-) diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index cb8380c..40c6071 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1177,6 +1177,30 @@ static void dm_table_set_integrity(struct dm_table *t) blk_get_integrity(template_disk)); } +static int device_nonrot(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + struct request_queue *q = bdev_get_queue(dev->bdev); + + return q && blk_queue_nonrot(q); +} + +static bool dm_table_all_nonrot(struct dm_table *t) +{ + unsigned i = 0; + + /* Ensure that all underlying device are non rotational. */ + while (i < dm_table_get_num_targets(t)) { + struct dm_target *ti = dm_table_get_target(t, i++); + + if (!ti->type->iterate_devices || + !ti->type->iterate_devices(ti, device_nonrot, NULL)) + return false; + } + + return true; +} + void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, struct queue_limits *limits) { @@ -1189,6 +1213,10 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q); else queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); + if (!dm_table_all_nonrot(t)) + queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q); + else + queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q); dm_table_set_integrity(t); -- 1.7.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/